Most image problems aren’t about the picture but the format. An iPhone photo won’t attach to a job application. An image saved from a website ends in .webp and your photo viewer refuses it. A logo gets a white box around it after “a quick conversion”.
This guide explains what JPG, PNG, WebP, AVIF and HEIC are good at (plus a short look at GIF and SVG), where each causes trouble, and which to pick for a website, social post, print or email.
Two ideas that explain almost everything
Lossy vs lossless. A lossy format (JPG, and the lossy modes of WebP, AVIF and HEIC) throws away detail your eye is unlikely to notice, which is how a 12-megapixel photo fits in a few megabytes. A lossless format (PNG, and the lossless modes of WebP and AVIF) keeps every pixel exactly: perfect for screenshots and graphics, huge for photos.
Transparency (alpha). PNG, WebP, AVIF and HEIC can store see-through pixels, which lets a logo sit on any background. JPG cannot. GIF only does on/off transparency, with no soft edges.
Ask those two questions (lossless? transparency?) and most decisions make themselves.
The formats, one by one
JPG (JPEG)
The universal photo format. Every phone, computer, browser, printer kiosk and upload form accepts it. It’s lossy and handles smooth gradients and real-world textures well, but it has no transparency and no animation.
Its weak spot is sharp edges: text, thin lines and flat graphics pick up blurry “halos”, especially at lower quality. And every edit-and-save as JPG loses a little more. One re-save is invisible; ten start to show.
PNG
Lossless, with full transparency. The right home for screenshots, diagrams, logos, text-heavy graphics and anything you’ll keep editing. Support is universal.
The catch is size. A photo saved as PNG is often several times larger than a good JPG of it, with no visible benefit. A 15 MB “photo.png” almost certainly should have been a JPG.
WebP
A web-first format that can be lossy or lossless, supports transparency and supports animation. All current major browsers display it, which is why so many sites now serve images as WebP. Compared with JPG at similar visual quality, lossy WebP is often around a quarter to a third smaller, though results vary a lot by image.
The gotcha: “Save image as” on a website gives you a .webp file, and some older desktop programs, office documents and upload forms still refuse it. The file isn’t broken; the other end just doesn’t know the format.
AVIF
A newer format based on the AV1 video codec. It usually compresses even better than WebP, supports transparency, animation and high dynamic range, and keeps gradients free of the blocky banding low-quality JPGs show. Current major browsers display it (Safari from 16.4), but older devices and many editing and office programs can’t open it, and encoding is slow.
HEIC (HEIF)
The iPhone’s default photo format. It’s efficient (often around half the size of an equivalent JPG) and can hold extras like depth data. Outside Apple devices it’s the format most likely to fail: Windows may need an add-on to open it, most browsers won’t display it, and many upload forms reject it.
To get JPG for new photos, set Settings → Camera → Formats → Most Compatible on your iPhone. Convert existing photos before sharing.
GIF and SVG, briefly
GIF is limited to 256 colors per frame, so photos look grainy and files get big. Its remaining strength: animated GIFs play almost everywhere, including email and chat.
SVG is a vector drawing described in code, so it stays razor-sharp at any size, ideal for website logos and icons. Most social platforms and many upload forms refuse it, and text in an SVG can change font on another computer if the font isn’t embedded.
Quick-pick table
| What you’re saving | Best choice | Also fine | Avoid |
|---|---|---|---|
| Photo to share or upload anywhere | JPG | — | PNG (too big), HEIC (may not open) |
| Photo on your own website | WebP or AVIF | JPG | PNG |
| Screenshot with text | PNG | lossless WebP | low-quality JPG |
| Logo or icon, website | SVG | PNG, WebP | JPG (no transparency) |
| Logo for upload or a document | PNG (transparent) | — | SVG (often refused) |
| Short animation for email or chat | GIF | — | animated WebP (may not play) |
| Photo for printing | High-quality JPG | PNG | WebP, AVIF, HEIC |
| Email attachment | JPG | PNG for graphics | HEIC, WebP, AVIF |
Choosing by where the image is going
Your own website or online shop. Heavy images slow pages down. Use WebP for most photos and graphics: JPG to WebP and PNG to WebP convert in batches, and transparency is kept. Around 80% quality is a good start. Resize first: a 4000-pixel photo in a 1200-pixel column wastes bandwidth in any format, so run it through Resize Image. Keep SVG for logos and icons.
Social posts. Upload JPG for photos and PNG for graphics with text. Platforms re-compress everything anyway, so a clean, reasonably sized JPG (say, 1080 pixels wide for a feed post) usually looks better than a giant file they shrink themselves. WebP and AVIF gain you nothing here.
Print. Send a high-quality JPG (90% or more) or a PNG at the full resolution the printer asks for. Many print shops and kiosks don’t take WebP, AVIF or HEIC. For logos, export the SVG with SVG to PNG at 4× or a set width; vectors redraw sharply at any size.
Email. Stick with JPG and PNG, which every email app displays. HEIC attachments often arrive as an unopenable file. Compress several phone photos first; a 75–80% JPG is plenty for screens.
Converting: what you gain, what you lose
Converting is easy. The trick is knowing which direction costs you something.
- Lossy → lossless (JPG to PNG) doesn’t bring back lost detail. It freezes the current quality for further edits, and the file gets bigger. JPG to PNG helps before editing, not as a quality fix.
- Lossy → lossy (HEIC, WebP or AVIF to JPG) re-compresses the image once more. At 85–92% quality it’s very hard to see, but don’t chain conversions; always start from the original.
- Anything with transparency → JPG fills the transparent areas, usually with white. That’s the “white box around my logo” problem; use PNG or WebP for logos.
- Animated → still keeps only the first frame, so an animated WebP becomes one JPG picture.
- Vector → pixels (SVG to PNG) is safe if you pick a big enough size. Choose 2× for sharp results on high-resolution screens.
Which tool fits each fix:
- iPhone photos that won’t open: HEIC to JPG converts batches into a ZIP (or to PNG if you’ll edit heavily). The first run takes a moment while the decoder loads.
- A .webp or .avif from a website: WebP to JPG or AVIF to JPG. AVIF decoding needs a reasonably current browser.
- A huge PNG photo: PNG to JPG usually makes it several times smaller.
- Any direction between JPG, PNG and WebP with a quality slider: Convert Image.
- Files that are just too big: Compress Image shrinks JPG, PNG and WebP in batches, can cap the longest side (say, 1920 px) and drops location data (EXIF).
- Stills that should move: GIF Maker builds an animated GIF from JPG, PNG or WebP images.
All of these run in your browser, so your photos are never uploaded.
Common mistakes
- Saving photos as PNG “for quality”. You get a much bigger file and no visible improvement. Use a high-quality JPG.
- Converting a logo to JPG. The transparent background turns white. Keep logos as PNG, WebP or SVG.
- Expecting JPG to PNG to fix blur or blocky artifacts. Lost detail stays lost.
- Re-saving the same JPG over and over. Keep the original and export each version from it.
- Uploading a giant image to a website. Resize to the size it’s actually shown at, then convert to WebP.
- Sending HEIC to someone on Windows. Convert to JPG first, or switch your iPhone to Most Compatible.
FAQ
Is WebP better than JPG?
For your own website, usually yes: it’s typically smaller at similar quality and supports transparency. For sending files to other people, uploading to forms or printing, JPG is still the safer choice because everything opens it.
Why can’t I open HEIC photos on Windows?
HEIC isn’t always supported out of the box on Windows, and most browsers and upload forms don’t handle it. Converting to JPG solves it, and setting your iPhone camera to Most Compatible prevents it for new photos.
Does converting HEIC to JPG lose quality?
Technically it re-compresses the photo once, but at high JPG quality (around 90%) the difference is very hard to spot. The JPG will usually be larger than the HEIC.
Should I use AVIF on my website in 2026?
It’s a good option when your visitors use current browsers, since files are often smaller than WebP. WebP remains the simpler, safer default, and a JPG or WebP fallback for older devices is sensible.
What’s the best format for a logo?
SVG on your own website, PNG with a transparent background everywhere else, and a large PNG exported from the SVG for print or uploads.